This invention relates to temperature probes having a thermistor responsive to the temperature to be measured which controls the output frequency of an oscillator to effect a temperature-frequency conversion. The invention is particularly applicable to oceanography systems in which the probe output is transmitted to a surface measuring station.
In some such systems, the oscillator in the probe is powered from a surface power source, and the probe output is transmitted to a surface detector. Because it is desirable to minimize probe size and cost, particularly where the probe is to be expendable, it is desirable to minimize the size of the cables transmitting power to and output from the probe. Smaller cable also increases the potential probe depth by allowing more cable to be packaged in the same volume. However, large cables and powerful oscillator outputs are ordinarily necessary to ensure a measurable signal at the surface station.